Device for automatically transporting dry granular material



Nov. 13, 1962 P. w. J. WIJDEVELD ETAL 3,063,755

DEVICE FOR AUTOMATICALLY TRANSPORTING DRY GRANULAR MATERIAL Filed March28, 1960 mvsu'rons PETRUS W.J.WIJDEVELD FRANS SCHOLTZE ADRIANUS F.BOSTERS United States Patent 3,063,7 55 DEVICE FOR AUTOMATICALLYTRANPORTWG DRY GRANULAR MATERIAL Petrus Wilhelmus Jozef Wijdeveld, FransScholtze, and Adrianus Franciscus Boaters, Baarn, Netherlands, assrgnorsto North American Philips Company, Inc, New

York, N.Y., a corporation of Delaware Filed Mar. 28, 1960, Ser. No.18,152 Claims priority, application Netherlands Mar. 31, 1959 2 Claims.(Cl. 302-58) The invention relates to a device for automaticallytransporting granular material.

It is frequently necessary to transport dry granular material with aminimum of manual handling in order to prevent contamination thereof.This is particularly the case when the material is granulatedpolyvinylchloride acetate, especially when used for pressing phonographrecords. It is also important that the transportation of the material bestopped automatically when the storage vessel to which the material isbeing conveyed is filled to a predetermined level and then be resumedautomatically when the amount of material drops below a certain level.

In accordance with the invention we transport the granular material bymeans of a device in which the material is agitated and then transportedby a stream of gas into the storage vessel through a tubular memberwhich is provided at one end with a closure member by which the how ofthe material can be readily controlled. More particularly the device,according to the invention, is characterized in that provision is madeof a transport duct, which has a mouthpiece provided with a central jetpipe and located at a certain distance from the sucking end of thetransport duct and capable of closing completely the mouth of thetransport duct against the pressure of a spring, whilst during operationa gas under a comparatively high pressure is conveyed through each jetpipe and the transport duct is furthermore provided with one or more jetpipes arranged in the wall thereof and extending approximately in thedirection of transport, which pipes are fed, during operation, also by agas under a comparatively high pressure.

According to a further aspect of the invention the mouthpiece is securedby means of at least two guides to a sliding piece surrounding thetransport duct, one of the guides being used as a supply duct for thegas.

The invention will be described more fully with refer ence to thedrawing, which shows one embodiment of the device according to theinvention and is a sectional view of the end of a transport duct.

In the drawing, reference numeral 1 designates a transport duct, whichhas a gland 2, secured rigidly to the duct. At the end of the duct isprovided a sliding piece 3, which is adapted to slide along the duct,and between the sliding piece 3 and the gland 2 is provided a pressurespring 4. The duct is provided with a bent-over edge 5, so that thesliding piece 3 cannot be removed fro-m the duct. A mouthpiece 6 isprovided with a jet pipe 7 and is secured by a connecting rod 8 to thesliding piece 3. The other connection between the sliding piece 3 andthe mouthpiece 6 is formed by a duct 9, to which a duct for compressedair is connected. The air has an overpressure of 3 to 4 atmospheres. Inthe wall of the duct are furthermore provided a plurality of jet pipes10, which are housed in a housing 11. This housing has a connection 12,through which also compressed air of 3 to 4 atmospheres can beintroduced into the housing 11. If the ice device described above isintroduced into a vessel containing, for example,polyvinylchloride-acetate grains, the mouthpiece 6 is urged against thelower end of the duct 1, so that there is no possibility for the lowerend of the duct 1 to contain a quantity of grains, which can not beconveyed. As soon as the mouthpiece 6 touches the bottom of the vessel,the spring urges the transport duct 1 upwards, so that a space is formedbetween the end of the duct 1 and the mouthpiece 6. If air is thenintroduced into the pipes 9 and 12, the fiow of air through the jet pipe7 agitats a quantity of grains. The grains obtain a certain initialvelocity and the air flowing through the jet pipes it] sucks up theagitated grains, which already have a certain velocity and transportsthem further. When such a quantity has been transported that the openingof the transport duct in the vessel, to which the grains to betransported are supplied, is completely closed, no grains are any longertransported, since the opening cannot be blown free, so that no flow ofair occurs any longer in the duct. When the opening is again free, thematerial being removed from the vessel, for example via a drain in thebottom or" the vessel, the transport is automatically resumed. With thedevice described above, a pipe diameter of 20 mms. and an air pressureof 3 to 4 atmospheres permitted of transporting per hour kgs. of grainsof polyvinylchloride acetate with a specific weight of 1.36 up to aheight of 4 metres. The air is previously purified by passing it througha filter. Any contamination of the polyvinylchloride is thus avoided.The device itself can be manufactured in a simple manner and it shouldbe noted that, for example, no cyclone is required to separate thematerial to be transported from the air. Moreover, it is found that acomparatively small quantity of air is required to transport of theaforesaid quantity.

What is claimed is:

1. A device for transporting dry granular material from one storagevessel to a second storage vessel, comprising a tubular transport memberhaving an inlet opening adapted to be imbedded in the material and anoutlet opening adapted to be arranged in the vicinity of the secondstorage vessel, a compressed gas jet mounted on said member with itsorifice within the member and directed toward the outlet opening, aclosure member movably mounted on said member at the inlet opening,resilient means urging said closure member away from the inlet openingto form a space, and a compressed gas jet mounted on said closure memberand directed through said space toward the inlet opening.

2. A device as defined in claim 1 and further comprising a plurality ofrod-shaped members slidably mounted on said transport member andsupporting said closure member, and means to supply gas to thecompressed gas jet on the closure member including a passageway formedin one of said rod-shaped members.

References Cited in the file of this patent UNITED STATES PATENTS469,175 Schutte Feb. 16, 1892 528,417 Duckham Oct. 30, 1894 850,639Gebhardt Apr. 16, 1907 1,305,726 Leonard June 3, 1919 2,561,148 SnowJuly 17, 1951 2,661,244 Baily Dec. 1, 1953 2,676,852 Kirkbride Apr. 27,1954 2,703,732 Schutte Mar. 8, 1955 2,774,636 Whitlock Dec. 18, 1956

